2 * ----------------------------------------------------------------------------
3 * "THE BEER-WARE LICENSE" (Revision 42):
4 * <phk@login.dkuug.dk> wrote this file. As long as you retain this notice you
5 * can do whatever you want with this stuff. If we meet some day, and you think
6 * this stuff is worth it, you can buy me a beer in return. Poul-Henning Kamp
7 * ----------------------------------------------------------------------------
9 * $FreeBSD: src/sys/kern/imgact_gzip.c,v 1.40.2.1 2001/11/03 01:41:08 ps Exp $
10 * $DragonFly: src/sys/kern/imgact_gzip.c,v 1.2 2003/06/17 04:28:41 dillon Exp $
12 * This module handles execution of a.out files which have been run through
13 * "gzip". This saves diskspace, but wastes cpu-cycles and VM.
16 * text-segments should be made R/O after being filled
17 * is the vm-stuff safe ?
18 * should handle the entire header of gzip'ed stuff.
19 * inflate isn't quite reentrant yet...
20 * error-handling is a mess...
22 * tidy up unnecesary includes
25 #include <sys/param.h>
27 #include <sys/imgact.h>
28 #include <sys/imgact_aout.h>
29 #include <sys/kernel.h>
32 #include <sys/resourcevar.h>
33 #include <sys/sysent.h>
34 #include <sys/systm.h>
35 #include <sys/vnode.h>
36 #include <sys/inflate.h>
39 #include <vm/vm_param.h>
42 #include <vm/vm_map.h>
43 #include <vm/vm_kern.h>
44 #include <vm/vm_extern.h>
47 struct image_params *ip;
57 u_long virtual_offset, file_offset, file_end, bss_size;
60 static int exec_gzip_imgact __P((struct image_params *imgp));
61 static int NextByte __P((void *vp));
62 static int do_aout_hdr __P((struct imgact_gzip *));
63 static int Flush __P((void *vp, u_char *, u_long siz));
66 exec_gzip_imgact(imgp)
67 struct image_params *imgp;
69 int error, error2 = 0;
70 const u_char *p = (const u_char *) imgp->image_header;
71 struct imgact_gzip igz;
73 struct vmspace *vmspace;
75 /* If these four are not OK, it isn't a gzip file */
77 return -1; /* 0 Simply magic */
79 return -1; /* 1 Simply magic */
81 return -1; /* 2 Compression method */
83 return -1; /* 9 OS compressed on */
86 * If this one contains anything but a comment or a filename marker,
87 * we don't want to chew on it
90 return ENOEXEC; /* 3 Flags */
92 /* These are of no use to us */
96 bzero(&igz, sizeof igz);
97 bzero(&infl, sizeof infl);
98 infl.gz_private = (void *) &igz;
99 infl.gz_input = NextByte;
100 infl.gz_output = Flush;
105 if (p[3] & 0x08) { /* skip a filename */
107 if (igz.idx >= PAGE_SIZE)
110 if (p[3] & 0x10) { /* skip a comment */
112 if (igz.idx >= PAGE_SIZE)
115 igz.len = imgp->attr->va_size;
117 error = inflate(&infl);
120 * The unzipped file may not even have been long enough to contain
121 * a header giving Flush() a chance to return error. Check for this.
123 if ( !igz.gotheader )
127 vmspace = imgp->proc->p_vmspace;
128 error = vm_map_protect(&vmspace->vm_map,
129 (vm_offset_t) vmspace->vm_taddr,
130 (vm_offset_t) (vmspace->vm_taddr +
131 (vmspace->vm_tsize << PAGE_SHIFT)) ,
132 VM_PROT_READ|VM_PROT_EXECUTE,0);
137 vm_map_remove(kernel_map, (vm_offset_t) igz.inbuf,
138 (vm_offset_t) igz.inbuf + PAGE_SIZE);
140 if (igz.error || error || error2) {
141 printf("Output=%lu ", igz.output);
142 printf("Inflate_error=%d igz.error=%d error2=%d where=%d\n",
143 error, igz.error, error2, igz.where);
155 do_aout_hdr(struct imgact_gzip * gz)
158 struct vmspace *vmspace;
162 * Set file/virtual offset based on a.out variant. We do two cases:
163 * host byte order and network byte order (for NetBSD compatibility)
165 switch ((int) (gz->a_out.a_magic & 0xffff)) {
167 gz->virtual_offset = 0;
168 if (gz->a_out.a_text) {
169 gz->file_offset = PAGE_SIZE;
171 /* Bill's "screwball mode" */
176 gz->virtual_offset = PAGE_SIZE;
180 /* NetBSD compatibility */
181 switch ((int) (ntohl(gz->a_out.a_magic) & 0xffff)) {
184 gz->virtual_offset = PAGE_SIZE;
188 gz->where = __LINE__;
193 gz->bss_size = roundup(gz->a_out.a_bss, PAGE_SIZE);
196 * Check various fields in header for validity/bounds.
198 if ( /* entry point must lay with text region */
199 gz->a_out.a_entry < gz->virtual_offset ||
200 gz->a_out.a_entry >= gz->virtual_offset + gz->a_out.a_text ||
202 /* text and data size must each be page rounded */
203 gz->a_out.a_text & PAGE_MASK || gz->a_out.a_data & PAGE_MASK) {
204 gz->where = __LINE__;
208 * text/data/bss must not exceed limits
210 if ( /* text can't exceed maximum text size */
211 gz->a_out.a_text > maxtsiz ||
213 /* data + bss can't exceed rlimit */
214 gz->a_out.a_data + gz->bss_size >
215 gz->ip->proc->p_rlimit[RLIMIT_DATA].rlim_cur) {
216 gz->where = __LINE__;
219 /* Find out how far we should go */
220 gz->file_end = gz->file_offset + gz->a_out.a_text + gz->a_out.a_data;
222 /* copy in arguments and/or environment from old process */
223 error = exec_extract_strings(gz->ip);
225 gz->where = __LINE__;
229 * Destroy old process VM and create a new one (with a new stack)
231 exec_new_vmspace(gz->ip);
233 vmspace = gz->ip->proc->p_vmspace;
235 vmaddr = gz->virtual_offset;
237 error = vm_mmap(&vmspace->vm_map,
239 gz->a_out.a_text + gz->a_out.a_data,
240 VM_PROT_ALL, VM_PROT_ALL, MAP_ANON | MAP_FIXED,
245 gz->where = __LINE__;
249 if (gz->bss_size != 0) {
251 * Allocate demand-zeroed area for uninitialized data.
252 * "bss" = 'block started by symbol' - named after the
253 * IBM 7090 instruction of the same name.
255 vmaddr = gz->virtual_offset + gz->a_out.a_text +
257 error = vm_map_find(&vmspace->vm_map,
262 FALSE, VM_PROT_ALL, VM_PROT_ALL, 0);
264 gz->where = __LINE__;
268 /* Fill in process VM information */
269 vmspace->vm_tsize = gz->a_out.a_text >> PAGE_SHIFT;
270 vmspace->vm_dsize = (gz->a_out.a_data + gz->bss_size) >> PAGE_SHIFT;
271 vmspace->vm_taddr = (caddr_t) (uintptr_t) gz->virtual_offset;
272 vmspace->vm_daddr = (caddr_t) (uintptr_t)
273 (gz->virtual_offset + gz->a_out.a_text);
275 /* Fill in image_params */
276 gz->ip->interpreted = 0;
277 gz->ip->entry_addr = gz->a_out.a_entry;
279 gz->ip->proc->p_sysent = &aout_sysvec;
288 struct imgact_gzip *igz = (struct imgact_gzip *) vp;
290 if (igz->idx >= igz->len) {
291 igz->where = __LINE__;
294 if (igz->inbuf && igz->idx < (igz->offset + PAGE_SIZE)) {
295 return igz->inbuf[(igz->idx++) - igz->offset];
298 error = vm_map_remove(kernel_map, (vm_offset_t) igz->inbuf,
299 (vm_offset_t) igz->inbuf + PAGE_SIZE);
301 igz->where = __LINE__;
306 igz->offset = igz->idx & ~PAGE_MASK;
308 error = vm_mmap(kernel_map, /* map */
309 (vm_offset_t *) & igz->inbuf, /* address */
310 PAGE_SIZE, /* size */
311 VM_PROT_READ, /* protection */
312 VM_PROT_READ, /* max protection */
314 (caddr_t) igz->ip->vp, /* vnode */
315 igz->offset); /* offset */
317 igz->where = __LINE__;
321 return igz->inbuf[(igz->idx++) - igz->offset];
325 Flush(void *vp, u_char * ptr, u_long siz)
327 struct imgact_gzip *gz = (struct imgact_gzip *) vp;
331 /* First, find a a.out-header */
332 if (gz->output < sizeof gz->a_out) {
333 q = (u_char *) & gz->a_out;
334 i = min(siz, sizeof gz->a_out - gz->output);
335 bcopy(p, q + gz->output, i);
339 if (gz->output == sizeof gz->a_out) {
344 gz->where = __LINE__;
348 gz->where = __LINE__;
352 if (gz->file_offset == 0) {
353 q = (u_char *) (uintptr_t) gz->virtual_offset;
354 copyout(&gz->a_out, q, sizeof gz->a_out);
358 /* Skip over zero-padded first PAGE if needed */
359 if (gz->output < gz->file_offset &&
360 gz->output + siz > gz->file_offset) {
361 i = min(siz, gz->file_offset - gz->output);
366 if (gz->output >= gz->file_offset && gz->output < gz->file_end) {
367 i = min(siz, gz->file_end - gz->output);
368 q = (u_char *) (uintptr_t)
369 (gz->virtual_offset + gz->output - gz->file_offset);
381 * Tell kern_execve.c about it, with a little help from the linker.
383 static struct execsw gzip_execsw = {exec_gzip_imgact, "gzip"};
384 EXEC_SET(execgzip, gzip_execsw);